Weighing scale



Jan. 14, w LLlAMs 2,027,504

WEIGHING SCALE Filed Aug. 16, 1954 4 Sheets-Sheet 1 Law ence 5. W////0/775 INVENTOR ATTORNEY Jan. 14, 1936. 5 WILUAMS 2,027,504

WEIGHING SCALE Filed Aug. 16, 1934 4 Sheets-Sheet 3 Lawrence [40/00/276 INVENTOR ATTORNEY Jan. 14, 1936. L. s. WILLIAMS 2,027,504

WEIGHING SCALE Filed Aug. 16, 1934 4 Sheets-Sheet 4 LOW/"e006 5 mmzms INVENTOR ATTORNEY Patented Jan. 14, 1936 UNITED STATES PATENT OFFICE WEIGHING SCALE Application August 16, 1934, Serial No. 740,140

7 Claims.

This invention relates generally to weighing scales, and more particularly to weighing scales of the so called cylinder type. Scales of this type having a cylindrical chart on which weight and value indicia are printed. Such charts are usually mounted on a horizontally disposed shaft, the ends of which rest in ball or other antifriction bearings and have a pinion seated on the horizontally disposed shaft which is engaged by a rack operatively connected to and actuated by a movable member of the load counterbalancing mechanism to rotate the chart. The pinions and racks employed for this purpose are very accurately cut and delicately balanced.

5 The chart, although designed and constructed as light as possible, has some inertia and there- -fore careless operation of the scale is apt to injure the teeth of the rack and pinion when the chart is set in motion, such injury might 0 lead to inaccurate weight indications.

The principal object of my invention is the provision of an improved indicator driving means.

Another object is the provision of improved means for obviating indication errors, in a weighing scale, which are caused by injuries to the teeth of racks and pinions.

Another object is the provision of plurality of a scale indicator driving racks.

Still another object is the provision of shock absorbing means in a scale indicator driving member; and,

A still further object is the provision of improved means for centering the scale indicating means.

These, and other objects and advantages will be apparent from the following description in which reference is had to the accompanying drawings, wherein similar reference numerals designate similar parts throughout the several views.

Referring to the drawings:--

Figure I is a back elevational view of a scale in which I have shown my invention embodied. Figure II is a side elevational view thereof.

Figure III is an enlarged fragmentary side elevational view of a pinion and rack construction showing their relative position at the instant of initiation of movement, when a load is placed on the scale.

Figure IV is a similar view of the pinion and rack construction when in a state of immobility.

Figure V is an enlarged side elevational view of my improved indicator driving means showing it in engagement with the pinion and the means for flexibly connecting the racks.

Figure V1 is a back view thereof showing a fragment of an indicating chart.

Figure VII is a plan view thereof.

Figure VIII is an enlarged fragmentary side elevational view of a modified form of pinion and rack construction; and,

Figure IX is a plan view thereof.

Referring to the drawings in detail:-

The scale in which I have shown my improved indicator driving means embodied represents a well known scale of the so called cylinder type comprising a base I, preferably in the form of a rigid iron casing having base horns 2 mounted thereon, these base horns 2 are provided in their upper ends with bearings 3, upon which fulcrum pivots 4 of a load supporting lever 5 are oscillably mounted. Load pivots 6, extending laterally from the arms of the lever 5, support bearings I fixed in downwardly extending arms of a load receiver supporting spider 8 surmounted by a load receiver 9. To insure a condition of level of the load receiver 9 the spider 8 is provided with a depending stem 19 which extends through an opening in the base I. Thelower end of this stem 10 engages one end of a check link II, the other end of which pivotally engages a depending bracket l2 forming a Roberval parallelogram. The bracket 12, although not shown herein, is usually provided with a universal mounting so that the hereinbefore referred to parallelogram can be accurately adjusted.

In addition to the pivots 4 and 6, fixed in the lever 5, it is provided with a nose pivot l3 in its opposite end, which engages a stirrup I4 suspended from a metallic tape l 5, whose upper end overlies an arcuate face of a power sector Hi to which it is fastened. This power sector I6 forms a part of the load counterbalancing pendulum ll of well known form, which is also provided with a stem 48 on which a pendulum weight I9 is adjustably threaded. A pivot 20, extending through the body of the pendulum l1, oscillably supports it on bearings 21 suitably stationed in hollow housing 22 securely fastened, adjacent one of the ends, to the base I.

Short laterally extending arms 23 (Figure I) adjacent the nose end of the lever 5, which projects into the interior of the housing 22, pivotally support a rack foot 24 to which a chucklike retainer 25 is fastened. This retainer 25 adjustably holds an upwardly extending rod 26 to the upper end of which a rack construction 21 is fastened. Teeth forming a part of the rack As hereinbefore mentioned, when a load is' carelessly thrown on the receiver 9 of the scale, a shock is transmitted through the medium of the lever 5, the rod 26 and the'teeth of the rack construction 21 to the teeth of the pinion" 23in overcoming the inertia of the chart 30. Al-

though this only occurs whenthescaleisabused.

by a careless operator, it has been found. desirable to provide means for obviating the results of suchshocks; I accomplish this byproviding two rack members 38.: and 39in my; construction.

The: member 38, which is considerably thicker than the rack member Y33 and: fixed inv the upper end of the rod 25," receives: all of. the shock at the initiation oftoperation of the weighing mechanismt. Theimember 39 is, secured to the member 38 by two substantially U. shaped flexible clips 40. 'I'heteethoftthisrack 39' constantly engage thezteeth of thepinion 28 while-:the teeth of the} rack. 38' are: so-positioned in relation tothe'teeth. of the pinion 28. that when theweighing; mechanism in a state. of: immobility they are not in contact. There are several Ways, of accomplishing this, .whichgive' equally desirable results, one is to make: the. legs. of the clip' 40 slightly difierent in length. so. when the pitch line-of' the'te'eth of. the rack 39 is in coincidence of the pitch line of the. pinion 28, the pitch line oftheteeth oi the rack 38-, although parallelto that of the. rack 39, isofiseta short distance. A similar-result is:obtained =when the: legs. of the U shaped. clips 40a (Figure IX): are. equal in length and the racks 38a=and 39a: mounted so that their pitch lines are coincident with. each other and with the pitchlineof the pinion 28a. The clearance between the teeth of therack 38a and'theteeth of the pinion 28wis: then obtained by: making the teeth of: the rack. 38a: thinner along thepitch line.

When a loadis now placed onthe load receiver 9' of the weighing mechanism, the nose end of thelever 5' is depressed and: the rack rod 26' with the rack construction 2? secured to its upper end moves downwardly' As. soon as the movement of' the rackis started, the inertia of the chart is sufficient to hold-the rack 39 stationary until additional force. flexes the clip =30 and permits the teeth of therack 38 to engage the -teethcof-thepinion 23 and the broad surface of'=the teeth of therack 38 transmitthe force to the chart and serve to rotate it through an angle proportional to the. weight of the load, and any wear" or mutil'ation resulting. from the shock of a careless and; rough applicationlofthe load it is takenvby these teeth and that portion of the pinion 28 engagedby: them.

Whenthe weighing mechanism has reached equilibrium that is, the weight of: the load has been=.-counterbalanced by the. pendulum mechanism, the tensionof the flexibleclip is sufiicient to return the'rack 33 to its-"proper position in relation: to -the rack-v 33, thus centering the. chart so that-the teeth of the pinion and the teeth of the rack 38 no longerengage :each other; Since,

due to the flexible mounting of the rack 39, all of the wear takes place between the teeth of the rack 38 and that portion of the teeth of the pinion 28 in contact with it, errors, due to such wear, are obviously eliminated.

It will be readily seen that the embodiments of my invention hereinbefore described are well suited to fulfill the objects primarily stated. However, it is to be understood that the embodiments herein shown are to be regarded illustrative only and that the invention is susceptible to variation, modification and change within the meaning and scope of the subjoined claims.

Having described my invention, I claim:

1. In. a device of" the class described, in combination, a rotatable indicator, means adapted to be actuated by force to move said indicator to indicating position. and to hold said indicator in indicating v position after cessation of such force, said means including a rack, means for moving said: rack endwise to various positions, a second rack, resilient means-connecting said racks; and yieldably holding them against relative longitudinal movement in. either direction, and a pinion, connected to said indicator, the'teeth, of said pinion being in constant mesh with theteeth of said second rack, the teeth of: saidpinion beingengageable with the teeth of the first said rack upon relative longitudinal movement of. said racks. in either direction.

2. In a device of the. class described, in com;- bination, a rotatable indicator, a pinion. asso. ciated: with said indicator, a plurality of racks cooperating with said pinion and teeth of one of said; racks engaging teeth ofsaid pinion only when said pinion is. moved or restrained by inertia.

3, In a device of the class described, in. com bination, a plurality of racks, means yieldably holding the axes of the teeth of said racks in substantial alignment, a pinion having teeth in meshing engagement with the teeth of one of said racks and out of contact with the teeth. of the other of said? racks, said racks being-relatively movable against. the action of said yieldable holding means to. bring the teeth of said other rack into contact with the teeth of said pinion.

4. In a device of the class described, in combination, a rotatable indicator, means for' operating said indicator, said operating means including a plurality of racks, the pitchlines of said racks being substantially parallel butoifset from each other with reference to a longitudinalbaseline drawn through one of said racks, yielding means connecting; said racks, one of said racks being constantly engaged with said pinion, the other: of said racks engaging, said pinion under the influence of inertia.

5.. Ina device of the class: described, in com:-v bination, a rotatable indicator, means for operating said rotatable indicator, said operating means including a pair of racks mounted in parallel planes and flexible means for connecting one ofsaid racks to the other, said flexible connecting means comprising. a substantially. U shaped member, one end of said U shaped member being secured to each of saidracks.

6. In a device of the class described, in combination, a rotatable indicator, means for operating said rotatable indicator including a pinion mounted on said rotatable indicator and a pair of racks, teeth of one of said racks being in contact with teeth of said pinion, yieldable means iorconnectingoneof said racks to the otherand yieldably holding the other of said racks with its teeth out of contact with the teeth of said pinion.

7. In a device of the class described, in combination, a rotatable indicator, a pinion associated with said indicator, 2. pair of racks cooperating with said pinion, teeth of one of said racks being normal in shape and teeth of the other rack being thinner than the chordal thickness of the teeth of the pinion.

LAWRENCE S. WILLIAMS. 

